ModuleServletTemplate.java

package servlets.module;

import dbProcs.Database;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import jakarta.servlet.http.HttpSession;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Locale;
import java.util.ResourceBundle;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.owasp.encoder.Encode;
import utils.Hash;
import utils.ShepherdLogManager;
import utils.Validate;

/**
 * SQL Injection Lesson - Does not use User Specific Key <br>
 * <br>
 * This file is part of the Security Shepherd Project.
 *
 * <p>The Security Shepherd project is free software: you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software Foundation, either
 * version 3 of the License, or (at your option) any later version.<br>
 *
 * <p>The Security Shepherd project is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 * PURPOSE. See the GNU General Public License for more details.<br>
 *
 * <p>You should have received a copy of the GNU General Public License along with the Security
 * Shepherd project. If not, see <http://www.gnu.org/licenses/>.
 *
 * @author name
 */
public class ModuleServletTemplate extends HttpServlet {

  private static final long serialVersionUID = 1L;
  private static final Logger log = LogManager.getLogger(ModuleServletTemplate.class);
  private static String levelName = "Level Name Here";
  public static String levelHash = "Level Hash Here";
  private static String levelResult =
      ""; // Put the Level Result Key here only if the level is not hardcoded in the database or

  // mobile application

  /**
   * Describe level here, and how a user is supposed to beat it
   *
   * @param aUserName Expected Parameters
   */
  public void doPost(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {
    // Dont Change any of this. This is logging player activity
    ShepherdLogManager.setRequestIp(request.getRemoteAddr(), request.getHeader("X-Forwarded-For"));
    PrintWriter out = response.getWriter();
    out.print(getServletInfo());
    // Translation Stuff
    Locale locale = new Locale(Validate.validateLanguage(request.getSession()));
    ResourceBundle errors = ResourceBundle.getBundle("i18n.servlets.errors", locale);
    ResourceBundle bundle =
        ResourceBundle.getBundle(
            "i18n.servlets.challenges.folder.fileNameWithoutExtention", locale);
    try {
      // Get the session from the request
      HttpSession ses = request.getSession(true);
      if (Validate.validateSession(ses)) // Is this an active session?
      {
        // Valid Session, time to log who it is
        ShepherdLogManager.setRequestIp(
            request.getRemoteAddr(),
            request.getHeader("X-Forwarded-For"),
            ses.getAttribute("userName").toString());
        log.debug(levelName + " servlet accessed by: " + ses.getAttribute("userName").toString());

        boolean returnKey = false;

        // Template Users: Edit from here
        String aUserName = request.getParameter("aUserName");
        log.debug(
            "User submitted aUserName: "
                + aUserName); // Log what the player submitted for your expected parameters

        // If you want to call a database function, this section if for you. All the way up until
        // if(returnKey)
        // Get Running Context of Application to make Database Call with
        String applicationRoot = getServletContext().getRealPath("");
        String output = doLevelSqlStuff(applicationRoot, aUserName, bundle);
        log.debug("Logging in English. Going to Output " + output);
        String htmlOutput =
            "<h2 class='title'>" + bundle.getString("module.example.header") + "</h2>";
        if (output == null) {
          htmlOutput += "<p>" + bundle.getString("module.example.outputWasNull") + "/p>";
        } else if (output.startsWith("123")) {
          log.debug("Setting Error Message");
          htmlOutput +=
              "<p>" + bundle.getString("example.error.123") + "</p>" + "<p>" + output + "</p>";
        } else {
          // Do some Database Stuff. Example assumes key is hardcoded and returned in the query from
          // the database
          // If you want to return a user specific key if the user has used SQLi to bypass
          // authentication or somthing, use the following bit of code for that
          returnKey = true;
        }
        if (returnKey) {
          // Something happened and now you want the user to be given a user specific key. then do
          // this
          String userKey =
              Hash.generateUserSolution(levelResult, (String) ses.getAttribute("userName"));
          log.debug("User has compelted level");
          // Otherwise just set userKey to "resultKey" and use the rest of this snip (If key is
          // hardcoded, make sure you set it that way in your database level entry)
          htmlOutput =
              "<h2 class='title'>"
                  + bundle.getString("module.example.completedHeader")
                  + "</h2>"
                  + "<p>"
                  + bundle.getString("module.example.theKeyIs")
                  + " "
                  + "<a>"
                  + userKey
                  + "</a>"
                  + "</p>";
        }
        log.debug("Outputting HTML");
        out.write(htmlOutput);
      } else {
        // Dont change this error
        log.error(levelName + " accessed with no session");
      }
    } catch (Exception e) {
      // Dont change this error
      out.write(errors.getString("error.funky"));
      log.fatal(levelName + " - " + e.toString());
    }
  }

  public static String doLevelSqlStuff(
      String applicationRoot, String username, ResourceBundle bundle) {

    String result = new String();
    try {
      // You will need to make a schema in the database/moduleSchemas.sql file, and define a user
      // which can access it.
      // The details of this user need to be entered in a properties file in WEB-INF/challenges
      // The Name of that user need to be entered in the following funciton;
      Connection conn =
          Database.getChallengeConnection(applicationRoot, "nameOfPropertiesFile.properties");
      Statement stmt;
      stmt = conn.createStatement();
      ResultSet resultSet =
          stmt.executeQuery("SELECT * FROM tb_users WHERE username = '" + username + "'");
      log.debug("Opening Result Set from query");
      for (int i = 0; resultSet.next(); i++) {
        log.debug("Row " + i + ": User ID = " + resultSet.getString(1));
        result = Encode.forHtml(resultSet.getString(1));
      }
      log.debug("That's All");
    } catch (SQLException e) {
      log.debug("SQL Error caught - " + e.toString());
      result =
          bundle.getString("example.error")
              + ": "
              + Encode.forHtml(e.toString()); // Html Encode Error to prevent XSS
    } catch (Exception e) {
      log.fatal(
          bundle.getString("example.error")
              + ": "
              + Encode.forHtml(e.toString())); // Html Encode Error to prevent XSS
    }
    return result;
  }
}